When two lines are crossed by another line (which is called the Transversal), the pairs of angles

• on opposite sides of the transversal

• but inside the two lines

are called Alternate Interior Angles.

When the two lines are parallel Alternate Interior Angles are equal.

Click on "Alternate Interior Angles" below to see.

• on opposite sides of the transversal

• but inside the two lines

are called Alternate Interior Angles.

When the two lines are parallel Alternate Interior Angles are equal.

Click on "Alternate Interior Angles" below to see.